The present invention relates to a reeling apparatus for reeling fiber web by which fiber web may be wound to successive reels, the reeling apparatus comprising a cutting device for cutting the web during a reel change, the cutting device being provided with at least one cutting head disposed movable in a direction essentially transverse to the web running direction to cut the web.
The invention also relates to a method for reeling a fiber web, according to which the web is wound to successive reels and according to which forming of a new reel is started during the reel change by guiding the paper web to the new reel as a strip or a wedge which is narrower than the full web width and which is cut from the paper web and spread to the full width of the web by cutting the paper web before the reeling.
A reel-up is generally used for example in continuous reeling of a paper web coming from a paper machine, a coating machine or a super calender. In the reeling, the web is wound onto a reel spool and the reel being produced is pressed against the reeling cylinder over which the web runs in a certain sector and which is rotated at a peripheral speed corresponding to the speed of the web.
Prior to the completion of the reel, a new reel spool, accelerated to the corresponding peripheral speed, may be brought to a nip contact with the reeling cylinder. Immediately when the reel has reached the desired size, a reel change is performed. There are different methods of changing the reel. The conventional way is as follows. The completed reel is moved away from the reeling cylinder. Then its rotating speed starts to slow down with the result that a web loop or a web bag is created between the reeling cylinder and the completed reel. This loop is guided for example by an air jet to be wound around a new reel spool whereby it is torn off from the completed reel.
Publication EP 543788 A1 discloses a method of reeling a web in which the web is cut in the reel change by means of a water jet or jets. At first, a tip is formed in the web which is guided around an empty reel spool. After this, the tip of the web is spread and in the end cut by extending the spreading over the edges of the web.
EP publication no. 089 304 A1 discloses a continuous reeling apparatus comprising means for performing a reel change. In this solution, there are slitting blades between the reeling cylinder and the guide roll preceding it by means of which, with a transverse crosswise movement, a strip can be at first formed in the web which is turned around an empty reel spool and, subsequently, the strip is spread and the web cut. The slitting blades of the solution have been provided in a shoe plate over which the web is made to run in a gliding contact during the slitting.
A solution and method like this, however, has for example the problem that when the web is cut with mechanical blades in free run of the web, the web must be kept relatively tight in order to achieve a good cutting result. For this reason the method is not suitable at all for paper grades which require a low web tension in the reeling such as particularly tissue. Further, this kind of supporting of the web including contact causes dusting and accumulation of dust. Dropping of a large dust particle onto the web undesirably also always increases the risk of a web break. Dust is accumulated in the structures and with time decreases the operation reliability of the equipment and increases the fire risk.
Particularly when reeling tissue, the web tension before the reeling apparatus is relatively low. Then the running of the web to the reeling cylinder is typically as such not sufficiently stable for the cutting of the wire with the free web feeding in the reel change.